Hunting drives rapid evolutionary change

January 16, 2009 Garry Peterson Leave a comment

The Fastest Way to Change a Species: Start Eating It from Science Now reports on a new PNAS paper by Chris Darimont et al (doi:10.1073/pnas.0809235106) that shows that human harvesting is driving rapid evolutionary change in many species:

According to a new analysis, the rate at which hunted and harvested species are changing their size and breeding schedules is unmatched in natural systems. Ecologists say the results point to errors in the way we manage fisheries and other harvested populations.

Researchers have noted rapid changes in heavily exploited fish and other species since the 1970s. To name one famous example, adult Atlantic cod (Gadus morhua) have decreased 20% in size over the past 30 years, and females now reproduce a year earlier than they used to (ScienceNOW, 31 January 2007). Although such hunting-induced alterations seem rapid, evolutionary biologist Chris Darimont of the University of Victoria in Canada, and colleagues wanted to determine whether they outpace changes in nonharvested organisms.

The team compiled 34 scientific papers that measured shifts over time in exploited species’ breeding schedules, overall size, or size of specific body parts. The studies included 29 species–mostly fish but also a few invertebrates, mammals, and plants. The team compared these studies with two databases: one for species such as Galápagos finches that had changed through natural selection and one for nonhunted species exposed to other human influences such as pollution or introduction to new habitats. All three categories included some rapid modifications, so “comparing the databases was kind of a showdown,” Darimont says.

Hunted organisms won hands down … Exploited species transformed on average three times faster than those in natural systems and 50% faster than species subject to other human interference. Moreover, almost all the exploited species–from bighorn sheep to the Himalayan snow lotus– were shrinking, breeding earlier, or both.

The human custom of taking a large percentage of the prey population and targeting the largest individuals–as with cod fishing–favors small individuals that breed before reaching trophy size, says Darimont. “[It’s a] perfect recipe for rapid trait change.” And it’s also bad news for the food supply: Smaller sizes and altered breeding schedules could decrease species’ abundance, hinder their ability to recover from exploitation, and ripple through ecosystems by altering interactions with predators and competitors. “When you start monkeying around with links in food webs,” Darimont warns, “there could be devastating results.”

Cities

Reflections on urban resilience

January 15, 2009 Garry Peterson 1 Comment

Two recent reflections on resilience in cities, which use different definitions of resilience than the resilience alliance. The first focuses on resilience as social trust and while the second on resilience as persistence.

Arjun Appadurai on the Immanent Frame writes: Is Mumbai’s resilience endlessly renewable?

Many well-meaning observers have stressed the “resilience”, the mutual generosity, the quotidian heroism and the remarkable resistance of Mumbaikars to jump to quick conclusions or hasty reprisals. I too congratulate and celebrate these facts. But I fear that all resilience is historically produced. And what history gives, history can take away. Yes, we are all Mumbaikars now. But in a world that links Mumbai, Kashmir, Karachi, Madrid, Peshawar, London, Wall Street, Washington and Faridkot, that is not necessarily a source of comfort. Resilience is a public resource. But, unlike terror, it is not indefinitely renewable.

In the Detroit Free Press columnist Sarah Webster quotes Steve Carpenter on resilience to explain why Detroit will come back in Detroit: Not a town of quitters:

If you’re from Detroit, you probably already know how much resilience has been fused into your bones.

This town is full of it.

In a YouTube video (Watch Carpenter explain it )posted by the Stockholm Resilience Centre, Professor Stephen Carpenter, who specializes in ecosystems at the University of Wisconsin, said resilience explains how things can “change and persist at the same time.”

“A resilient system could be able to withstand a shock without losing its basic functions,” he said. “A resilient system is able to transform to a different way of life when the current way of life is no longer feasible.”

But where resilience comes from – and why some people get it, while others don’t – isn’t a subject that’s very well understood. …

Like much of America, Detroit is full of immigrants. Those who came to Detroit, however, came to work in the factories at a time when factories weren’t so clean or safe, and there was a lot of competition for those $5 a day jobs. Factory work was for thick-skinned men who could breathe smoke, slog away near blazing fire pits of molten steel and assemble heavy car parts with their bare hands.

Wimps were not needed. Only the strong survived.

As somebody who came to Detroit just a decade ago, it seems to me that children of these immigrants – many of whom still work today in Detroit’s factories, or as engineers, designers and managers throughout the region – still know how to fight for what they believe in. And they seem to know that sometimes fights are best won in the final rounds, not in the early ones.

From time to time, I think it’s a good idea to remind folks what makes them so special — especially when they’re feeling down, as Detroit seems to be lately.

So, Detroit, know this: This is not a town of quitters.

And it’s why I feel so sure that Detroit, and its auto industry, will make a big comeback someday.

Regime Shifts

Elimination of cats drives trophic cascade

January 14, 2009 Garry Peterson 2 Comments

A new paper in the Journal of Applied Ecology (Bergstrom et al (2009). Indirect effects of invasive species removal devastate World Heritage Island, doi: 10.1111/j.1365-2664.2008.01601.x) describes how, on Macquarie Island, an important breeding location for several species of penguin, the elimination of invasive cats in attempt to protect the penguins has triggered a trophic cascade as herbivore populations have boomed defoliating the island.

The study’s lead author Dana Bergstrom, of the Australian Antarctic Division, estimates that nearly 40% has been modified, with 20% having moderate to severe change, and that rabbits have convert vegetation from complex communities to short, grazed lawns or bare ground.

Rabbits caused plant cover to decline starkly on this royal penguin "run" between 2001 (top) and 2007 (bottom). (From BBC)

Rabbits caused plant cover to decline starkly on this royal penguin "run" between 2001 (top) and 2007 (bottom). BBC

Finch Creek on sub-Antartic Macquarie Island. Rabbits have stripped 40% of the island bare of vegetation, scientists say. Photograph: /Australian Antarctic Division

From the Guardian:

Things began to go wrong on Macquarie Island, halfway between Australia and Antarctica, soon after it was discovered in 1810. The island’s fur seals, elephant seals and penguins were killed for fur and blubber, but it was the rats and mice that jumped from the sealing ships that started the problem. Cats were quickly introduced to keep the rodents from precious food stores. Rabbits followed some 60 years later, as part of a tradition to leave the animals on islands to give shipwrecked sailors something to eat.

Given easy prey, cats feasted on the hapless rabbits and feline numbers quickly grew. The island then lost two endemic flightless birds, a rail and a parakeet. Meanwhile, the rabbits bred rapidly and nibbled the island’s precious vegetation.

By the 1970s, some 130,000 rabbits were causing so much damage that the notorious disease myxomatosis was the latest foreign body introduced to Macquarie, which took the rabbit population down to under 20,000 within a decade.

“The island’s vegetation then began to recover,” Bergstrom says.

But what was good for the vegetation proved bad for the island’s wildlife. With fewer rabbits around, the established cats turned instead to local burrowing birds. By 1985, conservationists deemed it necessary to shoot the cats.

The last cat was killed in 2000, but the conservationists were horrified to see rabbit populations soar. Myxomatosis failed to keep numbers down, and the newly strong rabbit population quickly reversed decades of vegetation recovery. In 2006, the resurgent rabbits were even blamed for a massive landslip that wiped out much of an important penguin colony.

…
The Tasmanian Parks and Wildlife Service intends to fix the island once and for all, and has drawn up plans to eradicate all 130,000 rabbits, along with the estimated 36,000 rats and 103,000 mice that live there.

The move could yet provoke more unexpected side effects, Bergstrom says. “This is the largest island on which this type of eradication program will have been attempted.”

General

Shared pre-analytical vision, and groupthink and economics

January 13, 2009 Garry Peterson Leave a comment

On the Economix Blog, economist Uwe Reinhardt writes An Economist’s Mea Culpa that argues that economists have become locked into a too narrow pre-analytical vison of how the world works:

Fewer than a dozen prominent economists saw this economic train wreck coming — and the Federal Reserve chairman, Ben Bernanke, an economist famous for his academic research on the Great Depression, was notably not among them. Alas, for the real world, the few who did warn us about the train wreck got no more respect from the rest of their colleagues or from decision-makers in business and government than prophets usually do.

How could the economics profession have slept so soundly right into the middle of the economic mayhem all around us? Robert J. Shiller of Yale University, one of the sage prophets, addressed that question an earlier commentary in this paper. Professor Shiller finds an explanation in groupthink, a term popularized by the social psychologist Irving L. Janis. In his book “Groupthink” (1972), the latter had theorized that most people, even professionals whose careers ostensibly thrive on originality, hesitate to deviate too much from the conventional wisdom, lest they be marginalized or even ostracized.

If groupthink is the cause, it most likely is anchored in what my former Yale economics professor Richard Nelson (now at Columbia University) has called a ”vested interest in an analytic structure,” the prism through which economists behold the world.

This analytic structure, formally called “neoclassical economics,” depends crucially on certain unquestioned axioms and basic assumptions about the behavior of markets and the human decisions that drive them. After years of arduous study to master the paradigm, these axioms and assumptions simply become part of a professional credo. Indeed, a good part of the scholarly work of modern economists reminds one of the medieval scholastics who followed St. Anselm’s dictum “credo ut intellegam”: “I believe, in order that I may understand.”

Ecosystem services

Ecosystem service questions: Whose pollen? Whose pollinators?

January 13, 2009 Garry Peterson 1 Comment

As the world becomes more human dominated and people enclose an increasing number of ecological commons we can probably expect conflicts over ecosystem services to become more common. In California there is currently a new conflict over pollination. From Associated Press: Tangerine growers tell beekeepers to buzz off.

Is it trespassing when bees do what bees do in California’s tangerine groves?

…

Mega-grower Paramount Citrus has already sent letters to beekeepers near the company’s Kern County clementine groves threatening legal action and promising to seek “compensation for any and all damages caused to its crops, as well as punitive damages” if seeds develop. Company officials did not return phone calls seeking comment.

The new regulations would affect Kern, Tulare, Fresno and Madera counties in the southern San Joaquin Valley, where many orange growers converted to easy-to-peel tangerines. The fruit’s California acreage was expanded from 24,000 in 2005 to 31,392 in 2008 to compete with imports from Spain and the Middle East.

Tangerines and other normally seedless mandarins do not need bees to move pollen from the male to female parts of the flower in the process known as pollination. But if bees cross-pollinate the crop with the pollen of other fruit, mandarins develop undesireable seeds.

Almond trees on the west side of the valley, on the other hand, need lots of bees to pollinate. For the February pollination season, almond growers hire beekeepers from around the country to bring tens of thousands of hives to California, home to 70 percent of the world’s supply.

As almond blossoms drop in late March, citrus growers say, beekeepers relocate hives to make orange blossom honey before heading to the Midwest for spring clover season.

Some growers, who by law must ban spraying for citrus mites and other pests when bees are present, say the bees are an increasing burden.

“We’ve coexisted with them, but we don’t need them,” said Joel Nelson, executive director of California Citrus Mutual, a trade association. “Now we’re trying to adapt to changing consumer demands, and we’re hamstrung.”

I wonder if this means that allergy sufferers will be able to sue people who plant pollen producing plants?

via Agricultural biodiversity weblog

General

Mapping global hinterlands

January 11, 2009 Garry Peterson 1 Comment

Mapping travel time to cities of 50,000 or more people.

This map was made by Andrew Nelson from the Global Environmental Monitoring unit of the European Commission in collaboration with the World Bank’s Development Research Group. More data and details are available on the projects site: Travel time to major cities: A global map of Accessibility.

via Agricultural biodiversity weblog

General, Inequality

Oil Pirates of Nigeria

January 9, 2009 Garry Peterson Leave a comment

From the BBC Fighting for Nigeria’s oil wealth:

The Niger Delta, a region the size of England, is littered with violence and gas flares – the offshoot of oil extraction – whose roar and heat you can feel for hundreds of metres around.

The flares have become symbols of the region and the paradox that exists in an area where you find one of the world’s richest oil regions alongside some of the poorest people.

…
With unemployment at 90%, many people of the Delta are tempted to join the criminal gangs who terrorise the area, kidnapping foreign oil workers and launching raids on oil platforms.
…
Maintenance of the gangs, their boats and weapons is expensive and is funded by the theft of oil on a huge scale – up to 200,000 barrels a day.
…
The gangs are well-armed and the Joint Task Force is ill-equipped for the challenge.

They’ve managed to seize only a few of the barges used to ferry the stolen oil to huge tankers waiting offshore to take it on to the world’s refineries. It’s a huge and sophisticated operation on an international scale.

For more information on oil piracy see the Christian Science Monitor, PBS Newshour, and the BBC who write “Nigeria’s oil production has been cut by around a fifth since 2006, partly as a result of the violence by criminal gangs and militants. “

Adaptation, Ideas, Vulnerability

STEPS Centre Reframing Resilience report

January 9, 2009 Garry Peterson Leave a comment

Melissa Leach, director of the STEPS Centre, has written and posted a report on the Reframing Resilience symposium the centre hosted in Sept 2008 (Re-framing Resilience: A Symposium Report – pdf 484kb).

The symposium aimed to address questions such as:

How does resilience intersect with development and debates about it?
What insights does resilience thinking bring to understanding and action concerned with reducing poverty, vulnerability and marginalisation?
What are some of the frontier challenges, tensions and gaps as resilience thinking engages with perspectives and debates from other angles and disciplines?

Melissa Leach concludes her report by summarizing the final panel of the symposium:

a panel of speakers (Esha Shah, Andrew Scott, Henny Osbahr, Bronwyn Hayward, Joachim Voss, Carl Folke, Melissa Leach, Andy Stirling) offered their reflections on what had been learned, and what challenges and opportunities remain. Summarising across these discussions, a series of central themes emerged.

First, there is great value in a systems approach as a heuristic for understanding interlocked social-ecological-technological processes, and in analysis across multiple scales. Yet we need to move beyond both systems as portrayed in resilience thinking, and the focus on actors in work on vulnerability, to analyse networks and relationships, as well as to attend to the diverse framings, narratives, imaginations and discourses that different actors bring to bear.

Second, debates about resilience need to engage with normative concerns. This means that when we use terms like vulnerability and resilience we need to attach them to a person, form or organisation, rather than discuss them in the abstract. There is also a need to deal with the many trade-offs between people, systems, levels and scales in a normative way: someone’s resilience may be someone else’s vulnerability, or resilience at one scale may compromise that at another – but the key question is what trade-offs do we want or not want to see? Linking resilience with normative debates in this way may provide a valuable platform for critical discussion, helping to fill the current gulf between optimising and justice-based approaches in development, and contributing to the building of a new ethically and morally-driven development discourse.

Third, resilience approaches can be enriched through more disaggregated attention to action and strategies, considering transformations and transitions; endogeneity/exogeneity and depth of transitions; the relationships between functions, flows and structures; the dynamics (shocks/stresses) they address, and the agency (control/response) involved. We need to consider the processes through which actors at different levels decide strategies, and which would be enabling in terms of adaptiveness, learning, flexibility and empowerment.

Fourth, power and politics are crucial – as a growing area of resilience thinking that could valuably be strengthened with insights from other areas of work in politics, governance and democratic philosophy. Power relations are involved in assigning or avoiding responsibility and accountability; the domination of certain framings/narratives over others, asymmetries between pathways, and which are pursued and which are not. While resilience thinking is clear about the need to conserve life support systems, this will often require politically progressive thinking and action to challenge and transform unsustainable structures and framings in radical ways, and to hold powerful actors and networks to account. Depending on the issue and the setting, strategies might involve a spectrum from discursive and deliberative politics, to more antagonistic politics of resistance and struggle; all involve moves away from the managerialism that characterised early resilience approaches, towards conceptualising it in fundamentally political terms.

Finally, reframing and working with resilience involves an array of challenges for language and communication, and linking understanding and action. Resilience approaches involve complex language and concepts, and integration with other disciplinary perspectives can add to this complexity. A series of balances need to be struck, between attention to the nuances of different frameworks, and articulating their differences clearly; between conceptual advance, and remaining grounded in empirical settings; and between understanding complexity, and the clarity needed to inform policy and practice. The latter is crucial: policy decisions are being made as a matter of urgency in areas from climate change and energy to agriculture, water and health. Building resilience and pathways to Sustainability thus requires both reflection and reflexivity, and clear communication in terms that decision-makers can use.

Regime Shifts

Avoiding regime shifts is difficult

January 8, 2009 Garry Peterson 2 Comments

Conservation magazine’s Journal Watch Online returns from a long hiatus to report on an interesting new paper on the problems of detecting regime shifts by resilience researchers Oonsie Biggs, Steve Carpenter, and W.A. “Buz” Brock (2009. Turning back from the brink: Detecting an impending regime shift in time to avert it. PNAS DOI 10.1073/pnas.0811729106). They write:

Like the stock market, ecosystems can dramatically collapse. But how much advance notice is needed to prevent a natural system meltdown? A paper in Proceedings of the National Academy of Sciences says the answer might be several decades, which means today’s warning systems don’t detect changes nearly far enough in advance.

Using Northern Wisconsin’s sport fishery as a model, University of Wisconsin researchers determined when an ecosystem reaches the brink of an unstoppable shift, then estimated when recovery efforts must start in order to avert collapse. They found that some rapid actions only need short timetables; angling cuts can prevent permanent damage to fisheries even if they’ve been declining for ten years. But other changes, like restoring habitat after too much shoreline development, must start as many as 45 years before ecological health indicators start wobbling.

The problem is, most indicators in today’s early-warning systems can’t detect serious shifts that far out. Even if they could, it might still take policymakers years to enact recovery schemes. Which leads the authors to plea for indicators that work on a longer horizon, and for policy makers to move swiftly once scientists buy them some time.

Resilience Science